Agate from selected localities.
USA | |
| Cordua, W.S., 1998, "Minerals of Wisconsin", Rocks and Minerals vol. 73 #6, p. 378 - 399. |
Cordua, W.S., 1998, "Minerals of Wisconsin", Rocks and Minerals vol. 73 #6, p. 378 - 399. | |
| Cordua, W.S. (1990), Amygdule Minerals of the South Range Quarry, Douglas County, Wisconsin: Rocks and Minerals: 65: 412-415. |
Mabel Nelson Road Quarry, Douglas County, Wisconsin, USA